I am trying to lay some large wall tiles (17kg per m2) and believe I may have a problem because the existing wall is plaster. One idea is to remove the plaster and the fit a tile backerboard.

If I did this would a 6mm board be OK and would I just use tile adhesive to fix to the bare brick work?

You will be fine to remove the plaster and dot n dab plasterboard to the wall using plasterboard adhesive. much cheaper option than Wedi. You would need thicker than 6mm wedi for the walls I believe anyway. Bare plasterboard (unskimmed) will accept 32kg/m2 loading.

...Oh! and welcome to the forums.

Thanks grumpygrouter.

As an aside, do you think I am going to have a weight problem with the tiles I have chosen?

not with bare plasterboard.

It is not plasterboard but plaster on brick.

Hi ya,

although we have not got the large 2.4m boards have a look at our Thermopanel. Each board is 600x1200x10mm and is only £7.48 a board.
Have a look at the link below

**What a great Deal!**

Originally Posted by glynd

It is not plasterboard but plaster on brick.

Look down glynd.

Originally Posted by grumpygrouter

You will be fine to remove the plaster and dot n dab plasterboard to the wall using plasterboard adhesive.

Originally Posted by glynd

It is not plasterboard but plaster on brick.

It will be approaching the safe limits for that weight of tile on to plaster as you need to add the weight of adhesive and grout to it as well. Plaster will only accept 20kg/m2!

Hi ya,

Just for your information the thermal construction boards we sell will take loads up to 86kg/m2 and in tests done the adhesive failed and not the board!!

Originally Posted by Uheat - Aaron

Hi ya,

Just for your information the thermal construction boards we sell will take loads up to 86kg/m2 and in tests done the adhesive failed and not the board!!

Can you get me some info on that weight capacity Aaron....thats an awful lot of weight holding for a cement board...40kg to 45kg but 86kg......lordy thats alot...

So can you pm me some info stating that is so..please..

Originally Posted by Dave

Can you get me some info on that weight capacity Aaron....thats an awful lot of weight holding for a cement board...40kg to 45kg but 86kg......lordy thats alot...

So can you pm me some info stating that is so..please..

Have sent you a PM Dave,

From one of our manufacturers of Thermal Construction Board.

Boards were solid dabbed onto a wall. A paving slab (50cm x 50cm x 5cm @ 25kg) was glued to the board. Additional slabs were bonded to the first slab. In the end there were 6 slabs, 150kg, and it looked pretty dangerous but it still didnt fail.

The reduction to 87kg was similarly tested on a studded frame wall and failure occurred due to the flexing of the boards due to the pitch of the studded frame rather than any failure of the adhesion of the coating to the foam.

The boards come with a 10 year guarantee.

Hope this helps,

Thats a good price for those panels, only problem is I live in France. Not sure if you will deliver there

If I decide to go down the backerboard route does anyone know if I will get away with the 6mm ones using adhesive over the whole back to adhere to the brickwork?

Originally Posted by glynd

Thats a good price for those panels, only problem is I live in France. Not sure if you will deliver there

If I decide to go down the backerboard route does anyone know if I will get away with the 6mm ones using adhesive over the whole back to adhere to the brickwork?

we would deliver to france but would have to check on delivery costs which would depend on the order quantity/weight.

I will come back to you about the 6mm boards

You will be able to use 6mm Wedi as long as it is set full Bed,no dot and dab2Balls

2balls,

What thickness bed should I used and would that be a solid bed or a notched one?

Thanks

Morning, 8mm notched should do the trick,when the brick or block work is flat, use a grout float to tap in2Balls

Originally Posted by Uheat - Aaron

Boards were solid dabbed onto a wall. A paving slab (50cm x 50cm x 5cm @ 25kg) was glued to the board. Additional slabs were bonded to the first slab. In the end there were 6 slabs, 150kg, and it looked pretty dangerous but it still didnt fail.

The reduction to 87kg was similarly tested on a studded frame wall and failure occurred due to the flexing of the boards due to the pitch of the studded frame rather than any failure of the adhesion of the coating to the foam.

The boards come with a 10 year guarantee.

Hope this helps,

That doesn't sound very scientific to me, they are a couple of one-off tests!?! How did it hold up over time, under that load?

I'm not saying that these boards aren't great for the price, but i'd be very careful about quoting those weight limits.

Originally Posted by beanz

That doesn't sound very scientific to me, they are a couple of one-off tests!?! How did it hold up over time, under that load?

I'm not saying that these boards aren't great for the price, but i'd be very careful about quoting those weight limits.

Why would i need to be careful about quoting those weight limits?

The information has come direct from one of our suppliers of This product, they make a lot of these insulation boards, and are saying that the weights limits are acceptable on their product. If they are also supplying a 10 yr guarantee with the boards so why would i question it.

We also Sell Marmox Insulation Boards and these will hold up to 62kg/m2. I am sure if you were to speak with wedi technical they will quote you a slightly different figure.

Is there anyway of improving the load bearing capacity of plaster without having to remove all the plaster?

Perhaps by fixing backeboard on top of the plaster with both adhesive and mechanical fixings through the plaster and into the underlying brickwork?

Originally Posted by glynd

Is there anyway of improving the load bearing capacity of plaster without having to remove all the plaster?

Perhaps by fixing backeboard on top of the plaster with both adhesive and mechanical fixings through the plaster and into the underlying brickwork?

YES that will work also.....use adhesive to attach then fix as well....

Originally Posted by Uheat - Aaron

Have sent you a PM Dave,

From one of our manufacturers of Thermal Construction Board.

Boards were solid dabbed onto a wall. A paving slab (50cm x 50cm x 5cm @ 25kg) was glued to the board. Additional slabs were bonded to the first slab. In the end there were 6 slabs, 150kg, and it looked pretty dangerous but it still didnt fail.

The reduction to 87kg was similarly tested on a studded frame wall and failure occurred due to the flexing of the boards due to the pitch of the studded frame rather than any failure of the adhesion of the coating to the foam.

The boards come with a 10 year guarantee.

Hope this helps,

You say dabbed Aaron, any information on what they used to dab the boards on the wall with that weight. Thanks